Introduction to Wastewater Management
Why do we need wastewater treatment?
In many factories or even farms, we utilise multiple ingredients, many time including chemicals, as part of the manufacturing or value-added processes. When the products are made, there might be some wastes or residues left behind. Can we throw them away? No, since they might affect other living beings and the environment.
That’s why we need to treat the waste and ensure that whatever is being released back to the environment is safe and in compliance with the regulations. This ensure that we minimise the risk from harmful ingredients in our wastewater into the environment.
Wastewater is a complex mixture and may comprise of both organic and inorganic pollutants. The mixture may vary from industry to industry and that is why it is important to tailor the solution case by case.
Early Wastewater Management Practices
In the olden time, wastewater management was quite basic. Many early civilisations used simple sedimentation techniques as their wastewater treatment protocol. As newer industries emerged, the need for wastewater management also grows
This era can be a turning point where we were able to rapidly manufacture but also severely cause environmental pollution as well. The impact calls for more awareness and regulations to control the waste to the environment from these industries.
Modern Development of Treatment Technologies
Sophisticated treatment technologies start to be employed with new researches. From activated sludge processes to advanced biological treatments, wastewater management and treatment becomes an integral part of the industrial complexes.
Wastewater Treatment Process
Conventional wastewater treatment process has 3 major stages as follows:
1. Primary Treatment: Physical Separations
The first phase is a physical process where we try to filter solid materials in the liquid stream. This will help us filter out larger particles and suspended solids that are the results of the sedimentation or flotation processes. This process will help us remove the solid loads so that we can focus on the further treatment of the effluents.
2. Secondary Treatment: Biological Treatments
Next is the biological process where we use microorganisms like bacteria, protozoa, and etc. to help us in dissolving the organic matters in the effluents from the primary stage. This results in a floc-like structures or lumps that can be separated further from the effluent. Activated sludge systems and trickling filters are common methods used in this phase.
3. Tertiary Treatment: Residual Removals
The third stage is to further clear the effluent before discharging to the environment. This stage focuses on removing the remaining impurities or contaminants. Advanced treatment methods, such as chemical coagulation, filtration, and disinfection, are employed during this phase to achieve stringent water quality standards.
Additionally, there are also newer advancements such as:
Membrane filtration is a cutting-edge technology that utilizes semi-permeable membranes to separate impurities from water. This process effectively removes suspended solids, bacteria, and even some dissolved contaminants, producing a high-quality effluent. Common membrane filtration techniques include microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. These methods offer a finer level of control over the treated water’s quality, making them particularly valuable in industries where strict discharge standards must be met.
Advanced Oxidation Processes (AOPs)
Advanced Oxidation Processes involve the generation of highly reactive hydroxyl radicals to break down and transform complex organic pollutants into less harmful substances. AOPs, such as ozonation, photocatalysis, and Fenton’s reaction, are at the forefront of wastewater treatment innovation. They exhibit superior efficacy in degrading persistent pollutants that may resist conventional treatment methods. AOPs are particularly advantageous in addressing emerging contaminants and pharmaceutical residues, contributing to the overall resilience of wastewater treatment processes.
These technological advancements underscore our commitment to not only meet regulatory requirements but to surpass them, ensuring that our wastewater treatment processes are at the forefront of environmental stewardship and sustainable industrial practices.
Chemical pollutants, including heavy metals or Persistent Organic Pollutants (POPs) that are resistant to degradation (such as Polychlorinated Biphenyls (PCBs), Dioxins, DDT, Aldrin and Dieldrin, Hexachrolobenzene (HCB)), are often a challenge and require specialised treatment process
The volume of industrial wastewater or sludge is often overlooked and can pose a big challenge if not managed properly. It also can influence the cost of wastewater management as well. Less sludge will ensure limited impact to the environment and potentially the wastewater management cost.
Different countries have different regulations but with most countries slowly adopting stricter regulations to control waste level, the challenge will be to continuously improve and adopt out technology to be on par or even stricter than what the regulations require.
Key Innovations in Recent Times
Advanced Treatment Technologies:
Technologies such as advanced oxidation processes (AOPs) that generates highly oxidative hydroxyl compound (OH) to oxidise and breakdown inorganic materials and the electrochemical treatments that utilise electricity to induce chemical reactions to help breakdown materials are improving the ways we treat wastewater management to be more effective and efficient.
Smart and Integrated Systems:
Using digital systems, such as sensors help us track the processes at different stage and analyse the results, can help us identify the key areas in the wastewater management process that can further be improved to increase the overall process efficiency and be notified in time if there are any major issues that could pose a potential risks in the system.
Resource Recovery from Wastewater
Sludge often contains many chemical compounds, nutrients, as well as other resources that could be extracted and reused if we had the right tools. Such technologies can help to reduce the sludge volumes and also help reduce costs or generate profits through the extraction and reuse of the key resources that remained in the sludge.
Wastewater management will be continue to be an integral part of the manufacturing, farming, and other value-added industries. With new innovations, there will be new approaches and methods to further improve the efficiency of the process while reducing the amount of resources required to treat the waste which can minimise the impact on the environment.h